quest for sub equalization...

[curtis]

David,

Yes, all of these measurements are near a corner.....in fact, they are all withing three feet of each other. I have two more locations to try, but it requires rearranging some furniture. For reference, my room is 14x18, with a sloping ceiling that goes from 8' to 9'.

Interesting, I was messing around with the BFD lastnight to learn about it, and came up with this:

I also learned that taking measurements at different listening levels has a somewhat dramatic effect on FR.

Probably won't have much time to do much measuring today.

[BradJudy]

That looks like a great response there. I would be a bit worried about pushing the amp to hard if you added a 15db boost to defeat that dip.

[curtis]

Yeah....I know boost is usually a no no. I am going to send an email to Hsu about it. I was thinking that since I have a lot of headroom with the sub and my room, that it might be OK.

It sounds great at the listenning position...but really hot here at my computer in the next room through a doorway. I hear no distorting even at the highest of my listening levels.

[BradJudy]

I need to get myself an EQ to play with.

[Nicholas Mosher]

I'd be real careful about boosting that much, especially at relatively low frequencies. +15dB is a huge bump.

[curtis]

I'd be real careful about boosting that much, especially at relatively low frequencies. +15dB is a huge bump.

Totally understood....but had the sub volume extremely low, so I am thinking I have/had plenty of headroom. I'm not expecting this to be permanent....I still have other things to try. It was more of a BFD excersize.

Got to say, I am pretty pleased with the sound and extension, and still have that Hsu tonality. All the bass is there....but out of the way. Never realized I was getting useable extension below 15hz.

[bikeman]

"David, getting out of a corner does not mean you will get flatter response. Moving my sub one or two feet into the room along the wall got me a worse response curve."

Didn't mean to imply that it would always work that way. Just relating my experience.

David

[curtis]

My second position is about 3' from the corner, and 2' from the side wall.

[Nicholas Mosher]

Those HK whitepapers that describe ideal subwoofer placements are very impractical because they assume perfect conditions in a sealed perfectly square room. I definetly noticed less boom moving my sub from corners to "non-corner" positions though.

I can't believe your low-frequency extension is down only 5dB under-average at 10Hz though! Thats incredible with a 20Hz tune. With a 16Hz tune my SVS is down almost 15dB under-average at 10dB, and thats with 3 open ports. I'm curious as to what other VTF3 owners have seen for in-room response in the 10-20Hz range. What kind of peak SPLs are you getting in that max-extension mode Curtis?

[curtis]

I have never check for peaks. Give me a choice of material to test with and I will do some more measuring. I will also do some manual frequency measurements with my SPL meter. But below 20hz, it is pretty much all room gain. You can see by placing my sub in the second location, I lose everything below 50hz.

I can say, that as loud that I have played some movies, I have never bottomed the sub. This sub has more than I will ever need, in this room. Hsu has always stressed accuracy and sound quality, only the last couple of years has output become more popular because it is a spec you can see and most people relate to it easier. IMO, nobody in their right mind will be playing reference levels at home. For me, I would rather have a car that handles well than go fast if given the choice.

The VTF-3 has been measured flat to 18hz, and Hsu conservative specs 20hz +- 1dB....and 18hz +-2dB in max extension mode....max output gives you about 2dB in the upper bass area, while losing out below 22hz. I would give up anything under that to get rid of that canyon I have at about 38hz. Stuff below 16hz-18hz is just gravy to me.

I think I got that extra output down low by moving the sub just a couple of inches.

In the next couple of days I will try other locations and measurement...tonight I am going to just enjoy.